JP6320897B2 - Temperature control method - Google Patents

Description

  The present invention relates to a temperature control method used to control the temperature of various processes in the manufacture of semiconductors and the like, and more specifically, accurately achieves the temperature of various processes in the manufacture of semiconductors and the like while achieving energy saving and low cost. The present invention relates to a temperature control method that can be controlled.

  As is well known, when manufacturing semiconductors, flat panel displays (“FPD”), etc., it is necessary to perform temperature control in each process in order to achieve stable yield film formation, stable yield etching, and the like. .

  For this purpose, a temperature control device called a chiller has been conventionally used as a method for controlling these temperatures. That is, a control medium such as cold water is circulated between the chiller and various processes subject to temperature control, and the temperature of the control medium supplied to the various processes is controlled to a set temperature, thereby enabling various processes in semiconductor manufacturing. The temperature is to be controlled.

  Here, the configuration of a general chiller will be described with reference to FIG. 4. FIG. 4 is a diagram showing a circuit configuration of a chiller conventionally used, in which 51 is a chiller.

In general, the chiller 51 for controlling the temperature of various processes in semiconductor manufacturing supplies a control medium such as cold water and air to various processes to be temperature controlled and circulates the supplied control medium. A secondary circulation circuit 53 and a refrigerator 52 for controlling the temperature of a control medium supplied to various processes to be temperature controlled by the secondary circulation circuit 53 to a predetermined temperature are provided.

  That is, 52 shown by a dotted line in the figure is a refrigerator, and this refrigerator 52 has a refrigeration cycle as is well known, and this refrigeration cycle includes a primary side circulation circuit 61 for circulating a refrigerant. The compressor 55, the condenser 56, the expansion valve 57, and the evaporator 58 are arrange | positioned in the middle of this primary side circulation circuit 61.

  Then, the refrigerant is circulated between the compressor 55, the condenser 56, the expansion valve 57, and the evaporator 58 by the primary side circulation circuit 61, and returns to the evaporator 58 through the secondary side circulation circuit 53. The temperature of the control medium is controlled to a predetermined temperature by exchanging heat between the control medium and the refrigerant circulating in the primary side circulation circuit 61.

  That is, in the refrigerator 52, the refrigerant vaporized by the evaporator 58 is compressed to a high pressure in the compressor 55, and the refrigerant increased in pressure by the compressor 55 is condensed by heat exchange in the condenser 56. The refrigerant liquefied in 56 is reduced in pressure in the expansion valve 57, and then the refrigerant is vaporized in the evaporator 58, whereby heat is returned from the control medium returned to the evaporator 58 via the secondary side circulation circuit 53. Stealing and lowering the temperature of the control medium.

  Further, in the conventional chiller 51, the heater 63 is disposed on the supply side in the secondary side circulation circuit 53, and the temperature of the control medium cooled in the evaporator 58 is increased to a set temperature. That is, since the conventional refrigerator cannot perform fine temperature control, the temperature of the control medium is set to the set temperature by heating the control medium to a temperature lower than the set temperature and then heating by the heater 63.

  In the figure, reference numeral 67 denotes drive means for circulating the controlled object in the secondary side circulation circuit 53. When cold water is used as the control medium, it is a pump, and air is used as the control medium. If you are a fan.

  In the figure, 54 is a cooling water circulation circuit for supplying cooling water to reduce the temperature of the refrigerant in the condenser 56 to condense, 59 in the figure 59 is an accumulator, and 65 in the figure is the operation of the entire apparatus. It is control means, such as a microcomputer, for controlling.

  Further, in the figure, reference numeral 62 denotes a hot gas bypass circuit for mixing the refrigerant discharged from the expansion valve 57 with the refrigerant before being cooled in the condenser 56. In the path of the hot gas bypass circuit 62, An expansion valve 60 for hot gas is arranged. That is, the conventional refrigerator 52 includes a hot gas bypass circuit 62 and a hot gas expansion valve 60 in order to prevent the temperature of the control medium from being cooled more than necessary in the evaporator 58. Then, the hot gas expansion valve 60 is opened, the high temperature refrigerant discharged from the compressor 55 is mixed with the refrigerant discharged from the expansion valve 57, and the temperature of the refrigerant supplied to the evaporator 58 is increased, whereby the control medium is Prevents the temperature from becoming lower than necessary.

JP 2002-023862 A Japanese Patent Application Laid-Open No. 07-151441

  As described above, in the conventional chiller 51, the control medium that has returned to the refrigerator 52 through the secondary side circulation circuit 53 is once cooled to a temperature lower than the set temperature in the refrigerator 2, and then the heater 63 In order to keep the burden on the heater 63 low, the pressure is reduced by the expansion valve 57 by the hot gas bypass circuit 62 and the hot gas expansion valve 60. By mixing hot gas with the obtained refrigerant, the temperature of the refrigerant supplied to the evaporator 58 is raised, thereby preventing the control medium from being cooled more than necessary.

  However, in the conventional chiller 51, temperature sensors 64 are arranged before and after the heater 63, and the temperature sensor 64 detects the temperature of the control medium in the secondary side circulation circuit 53, and the temperature is determined in advance. The opening and closing of the hot gas expansion valve was controlled only on the basis of whether the temperature was higher or lower. Therefore, by opening the hot gas expansion valve 60 and increasing the temperature of the refrigerant supplied to the evaporator 58, the burden on the heater can be reduced somewhat, but the temperature of the control medium cannot be finely controlled. Heating by the heater 63 is necessary, and therefore it is difficult to reduce the cost of the entire apparatus.

  In addition, the supply of hot gas in the conventional chiller controlled the expansion valve for hot gas independently, ignoring the total refrigerant circulation amount in the refrigeration cycle, so the work load of the compressor was maintained. In the worst case, the compressor could stop due to a high pressure abnormality.

  Therefore, an object of the present invention is to provide a temperature control method capable of controlling the temperature of a control medium to a set temperature while achieving energy saving and cost saving.

The temperature control method of the present invention is a temperature control method for controlling the temperature of a control medium supplied to a temperature control target in various processes in semiconductor manufacturing to a predetermined temperature,
A primary side circulation circuit for circulating the refrigerant;
A compressor arranged in the middle of the primary side circulation circuit for compressing vaporized refrigerant to a high pressure, a condenser for condensing the refrigerant made high pressure by the compressor by heat exchange, and the condenser A cooling expansion valve for reducing the pressure of the liquefied refrigerant, and a heat exchanger for controlling the temperature of the control medium to a set temperature by vaporizing the refrigerant made low pressure by the cooling expansion valve;
A bypass circuit for hot gas that connects between the compressor and the condenser and between the cooling expansion valve and the heat exchanger in the primary side circulation circuit;
An expansion valve for hot gas, which is arranged in the middle of the bypass circuit for hot gas, for mixing the high-temperature refrigerant made high in pressure by the compressor with the refrigerant made low in pressure by the cooling expansion valve;
A refrigerator comprising:
A secondary circulation circuit that circulates the control medium between the temperature control target and the heat exchanger, and supplies the control medium controlled to a predetermined temperature in the heat exchanger to the temperature control target;
Using a temperature control device equipped with
A temperature sensor is arranged in the path of the secondary side circulation circuit,
According to the detection result by the temperature sensor, by adjusting the opening of the cooling expansion valve and the hot gas expansion valve, to control the temperature of the control medium supplied to the temperature adjustment target to a set temperature , By controlling the opening degree of the cooling expansion valve and the opening degree of the hot gas expansion valve in inverse proportion to each other, the amount of refrigerant supplied to the heat exchanger is adjusted to be constant, and thereby the primary side The circulation amount of the refrigerant in the circulation circuit is made constant .

  The temperature control method of the present invention includes a compressor, a condenser, a cooling expansion valve, and a heat exchanger, and a hot gas that mixes a high-pressure refrigerant that has been increased in pressure by a compressor with a refrigerant that has been reduced in pressure by a cooling expansion valve. In the method of controlling the temperature of the control medium supplied to the temperature adjustment target to the set temperature using the refrigerator equipped with the expansion valve for the temperature, a temperature sensor for detecting the temperature of the control medium supplied to the temperature adjustment target is arranged. Then, according to the detection result by the temperature sensor, the opening degree of the cooling expansion valve and the hot gas expansion valve is adjusted, thereby controlling the temperature of the control medium supplied to the temperature adjustment target to the set temperature. Yes.

Therefore, unlike conventional chillers that control only the opening and closing of the hot gas expansion valve based on whether the temperature of the control medium is higher or lower than a predetermined temperature, fine temperature control can be performed. For this reason, it is not necessary to cool the control medium below the set temperature and then heat it with the heater to reach the set temperature, so that the heater becomes unnecessary, and energy saving and low cost can be achieved. In addition, when adjusting the opening of both the cooling expansion valve and the hot gas expansion valve, heat exchange is performed by controlling the opening of the cooling expansion valve and the opening of the hot gas expansion valve in inverse proportion to each other. Since the amount of refrigerant supplied to the compressor is adjusted to be constant, it is possible to keep the amount of refrigerant circulating in the primary side circulation circuit constant, and the compressor work is kept constant. Can be stabilized.

It is a block diagram for demonstrating the structure of the chiller used for the Example of the temperature control method of this invention. It is a block diagram which shows the control system of the chiller used for the Example of the temperature control method of this invention. It is a flowchart for demonstrating the Example of the temperature control method of this invention. It is a block diagram for demonstrating the structure of the conventional chiller.

In the temperature control method of the present invention, a control medium is supplied to a temperature control target in various processes in manufacturing semiconductors and the like, and the supplied control medium is circulated to a set temperature and then supplied to the temperature control target again. Using the refrigerator for controlling the secondary side circulation circuit and the temperature of the control medium circulating in the secondary side circulation circuit to the set temperature, the temperature of the control medium supplied to the temperature control target by the refrigerator is the set temperature. We are going to control it.

  And the refrigerator has the primary side circulation circuit which circulates a refrigerant | coolant similarly to a general refrigerator, and compresses the vaporized refrigerant to high pressure in the middle of this primary side circulation circuit. The compressor, a condenser for condensing the refrigerant having a high pressure by the compressor by heat exchange, a cooling expansion valve for reducing the pressure of the refrigerant liquefied by the condenser, and a low pressure by the cooling expansion valve The control medium that has circulated from the temperature control target through the secondary side circulation circuit is cooled by heat exchange with the vaporized refrigerant in the heat exchanger. It is said.

  The refrigerator has a hot gas bypass circuit and a hot gas expansion valve. The hot gas bypass circuit includes a compressor and a condenser, and a cooling expansion valve in the primary circulation circuit. A hot gas expansion valve is placed in the middle of the connection with the heat exchanger, and the hot gas expansion valve is opened, so that the refrigerant is made low in pressure by the cooling expansion valve, and high in pressure by the compressor. A high-temperature refrigerant can be mixed at a low pressure.

  In the temperature control method of the present invention, the temperature sensor is arranged in the secondary side circulation circuit to monitor the temperature of the control medium circulating in the secondary side circulation circuit, and the cooling is performed based on the temperature detected by the temperature sensor. The opening of both the expansion valve for hot gas and the expansion valve for hot gas is adjusted, thereby adjusting the temperature of the refrigerant supplied to the heat exchanger, so that the temperature of the control medium exchanged with the refrigerant is adjusted. The set temperature is set.

In the temperature control method of the present invention, when adjusting the opening degree of both the cooling expansion valve and the hot gas expansion valve, the opening degree of the cooling expansion valve and the opening degree of the hot gas expansion valve are made inversely proportional to each other. The amount of refrigerant supplied to the heat exchanger is adjusted to a constant level, which keeps the amount of refrigerant circulating in the primary circulation circuit constant and keeps the compressor work constant. Thus, the operation can be stabilized.

An embodiment of the temperature control method of the present invention will be described. In the temperature control method of this embodiment, various processes in manufacturing a semiconductor, a flat panel display (“FPD”), and the like are targeted for temperature control, and supplied to this temperature control target. This is a method for controlling the temperature of the control medium that performs temperature control of the temperature adjustment target to the set temperature, and the temperature control of the control medium uses a chiller as in the conventional method.

  Here, the chiller used in the temperature control method of the present embodiment will be described. FIG. 1 is a block diagram showing the configuration of the chiller for carrying out the temperature control method of the present embodiment. And in the figure, 1 is a chiller, and the chiller 1 used for the temperature control method of a present Example is equipped with the refrigerator similarly to the chiller generally used.

  That is, reference numeral 2 shown by a dotted line in the figure is a refrigerator, and the refrigerator 2 used in the temperature control method of the present embodiment is a primary-side circulation that circulates a refrigerant in the same manner as a generally used refrigerator. A circuit 3 is provided. A compressor 4 for compressing the vaporized refrigerant to a high pressure in the middle of the primary circulation circuit 3 and a refrigerant having a high pressure by the compressor 4 are condensed by heat exchange to form a high-pressure liquid. The condenser 5, the cooling expansion valve 6 for lowering the refrigerant liquefied by the condenser 5, and the refrigerant made low pressure by the cooling expansion valve 6 are vaporized to exchange heat with the control medium. A heat exchanger 7 as an evaporator is provided.

  In the figure, reference numeral 10 denotes an accumulator. The accumulator 10 is used to prevent the refrigerant that has not been vaporized by the heat exchanger 7 from being sucked into the compressor 4 as a liquid.

  Further, in the refrigerator 2 used in the present embodiment, in order to prevent the temperature of the refrigerant supplied to the heat exchanger 7 from becoming unnecessarily low, as in the conventional refrigerator described above, It has a bypass circuit and a hot gas expansion valve. That is, in the figure, 8 is a hot gas bypass circuit, and one end of the hot gas bypass circuit 8 is connected to the primary circuit 3 between the compressor 4 and the condenser 5, and the other end is The primary expansion circuit 3 is connected between the cooling expansion valve 6 and the heat exchanger 7.

  A hot gas expansion valve 9 is interposed in the middle of the hot gas bypass circuit 8. By opening the hot gas expansion valve 9, the high-temperature refrigerant that has been increased in pressure by the compressor 4 is heated. After the pressure is reduced by the gas expansion valve 9, the refrigerant is mixed with the refrigerant that has been reduced by the cooling expansion valve 6.

  In this embodiment, the cooling expansion valve 6 and the hot gas expansion valve both use electronic expansion valves and operate by driving a stepping motor in accordance with a pulse signal from a pulse converter (not shown). However, since the electronic expansion valve is well known, detailed description is omitted.

  Next, in the figure, 11 is a cooling water circulation circuit, and this cooling water circulation circuit 11 is used in order to condense the gaseous refrigerant | coolant made into the high voltage | pressure high temperature with the compressor 4 by heat exchange.

  The cooling water circulation circuit 11 is connected to a cooling water production apparatus such as a cooling tower (not shown), and supplies the cooling water cooled by the cooling tower or the like to the condenser 5. Heat is exchanged in the circuit, so that the cooling water after the temperature rises is circulated to the cooling tower or the like.

  In the figure, reference numeral 12 denotes a secondary side circulation circuit. In this embodiment, the secondary circulation circuit 12 is controlled to the set temperature while circulating the control medium between the heat exchanger 7 and various processes in the manufacture of semiconductors and the like, which are to be temperature controlled. It is used for supplying a control medium to a temperature control target and controlling the temperature of the control medium circulated from the temperature control target to a set temperature.

  In this embodiment, cold water is used as the control medium, and the cold water supply path 1201 for supplying the cold water whose temperature has been lowered by the heat exchanger 7 to the temperature adjustment target, and the temperature rise in the temperature control target. The chilled water circulation path 1202 for returning the chilled water to the heat exchanger 7 is provided, and a temperature sensor 13 for detecting the temperature of the chilled water supplied to the temperature control target is provided on the cold water circulation path 1202 side. It is arranged to constantly monitor the temperature of the cold water supplied to the temperature control target. In the figure, reference numeral 15 denotes a pump for circulating cold water in the secondary side circulation circuit.

  Next, the temperature control method of the present embodiment for setting the temperature of the cold water to the set temperature using the chiller 1 configured as described above will be described. In the temperature control method of the present embodiment, the entire operation of the chiller 1 is described. As shown in FIG. 2, the control means 14 includes at least the temperature sensor 13, the compressor 4, the cooling expansion valve 6, and the hot gas expansion, as shown in FIG. The valve 9, the pump 15, and the power source are connected to control the operation of the compressor 4, the cooling expansion valve 6, the hot gas expansion valve 9, the pump 15, and the like.

  Then, the control means 14 controls the opening degree of the cooling expansion valve 6 and the hot gas expansion valve 9 according to the detection signal from the temperature sensor 13, so that the temperature of the cold water becomes the set temperature. Necessary refrigerant is supplied to the heat exchanger 7.

  That is, in the temperature control method of the present embodiment, the temperature of the coolant necessary for setting the temperature of the chilled water supplied to the temperature adjustment target corresponding to the temperature of the chilled water circulated from the temperature adjustment target in advance is set. Set it.

  At the same time, the opening degrees of the cooling expansion valve 6 and the hot gas expansion valve 9 necessary for setting the temperature of the refrigerant supplied to the heat exchanger 7 to the set temperature are set.

  And based on the setting, the control means 14 controls the opening degree of the cooling expansion valve 6 and the hot gas expansion valve 9 according to the temperature of the cold water circulating from the temperature control object, Refrigerant having a temperature necessary for achieving the set temperature is supplied to the heat exchanger 7, whereby the temperature of the cold water circulated from the temperature adjustment target is set to the set temperature in the heat exchanger 7. It is possible.

  That is, in FIG. 3, the compressor 4 is driven in S <b> 1, the refrigerator is operated, and the refrigerant is circulated in the primary side circulation circuit 3.

  At the same time, in S2, the pump 15 is driven to circulate cold water in the secondary side circulation circuit 12.

  In the process of circulating the refrigerant and the cold water, the temperature of the cold water is detected by the temperature sensor 13 in S3, and the opening degree of the cooling expansion valve 6 is determined in S4 and S5 according to the detection result of the temperature sensor 13. Then, the opening degree of the hot gas expansion valve 9 is adjusted, whereby the refrigerant having the set temperature is supplied to the heat exchanger 7 and the temperature of the cold water supplied to the temperature adjustment target is controlled to the set temperature.

  At this time, in the temperature control method of this embodiment, the opening degree of the cooling expansion valve 6 and the opening degree of the hot gas expansion valve 9 are controlled in inverse proportion to each other, and the cooling expansion valve 6 comes out. By making the total amount of the refrigerant and the refrigerant coming out of the hot gas expansion valve 9 constant, the amount of the refrigerant supplied to the heat exchanger 7 is made constant. Therefore, according to the temperature control method of the present embodiment, the circulation amount of the refrigerant circulating in the primary side circulation circuit 3 can be maintained constant, and the work amount of the compressor 4 can be maintained constant and the operation can be performed. Can be stabilized.

  Next, the operation of the temperature control method of the present embodiment will be described. In the temperature control method of the present embodiment, as described above, a heat exchanger corresponding to the temperature of the cold water circulated from the temperature adjustment target in advance. In step 7, the temperature of the refrigerant necessary for setting the temperature of the cold water to the set temperature is set. At the same time, the opening degrees of the expansion valve 6 for cooling and the expansion valve 9 for hot gas necessary for obtaining the temperature of the refrigerant are set.

  Further, at that time, the opening degree of the cooling expansion valve 6 and the opening degree of the hot gas expansion valve 9 operate in inverse proportion to each other, and from the refrigerant coming out of the cooling expansion valve 6 and the hot gas expansion valve 9 The total amount of refrigerant that comes out is set to be constant.

  Then, the secondary side circulation circuit 12 circulates cold water between the heat exchanger 7 of the refrigerator 2 and the temperature control target, and the temperature of the cold water is controlled to the set temperature in the heat exchanger 7 using the refrigerator 2. At that time, according to the temperature of the cold water circulating from the temperature adjustment target, the temperature of the cold water supplied to the temperature control target is set to a preset temperature, that is, in the heat exchanger 7. The opening degree of the cooling expansion valve 6 and the hot gas expansion valve 9 is controlled so that the temperature of the supplied refrigerant becomes the set temperature.

  Then, in the heat exchanger 7, it is possible to supply the heat exchanger 7 with the refrigerant controlled to a temperature necessary for setting the chilled water to the set temperature, whereby the chilled water can be set to the set temperature. It becomes possible to supply the cold water made to the temperature control object.

  As described above, in the temperature control method of the present embodiment, the opening degrees of the cooling expansion valve and the hot gas expansion valve are adjusted according to the temperature of the cold water circulating from the temperature control target, and thereby the temperature control is performed. Since the temperature of the cold water supplied to the target is controlled to the set temperature, only opening and closing of the hot gas expansion valve is performed based on only whether the temperature of the control medium is higher or lower than a predetermined temperature. Unlike the conventional chiller which has been controlled, the temperature of the refrigerant is finely controlled, and therefore the temperature of the cold water can be set to the set temperature in the heat exchanger. Therefore, according to the temperature control method of the present embodiment, a heater for heating the chilled water cooled below the set temperature by the refrigerator to the set temperature becomes unnecessary, and energy saving and low cost can be achieved.

  In the above description, the case where the cold water is circulated in the secondary side circulation circuit 12 is described. However, the cold water is not necessarily circulated, and any other liquid, gas, or the like may be circulated.

  In the temperature control method of the present invention, in a method for controlling the temperature of various processes in the manufacture of semiconductors and the like using a chiller, while achieving energy saving and low cost, cold water supplied to various processes to be temperature controlled, etc. Since the temperature of the control medium can be controlled, the present invention can be applied to all methods of supplying a control medium having a predetermined temperature to a temperature control target using a chiller.

DESCRIPTION OF SYMBOLS 1 Chiller 2 Refrigerator 3 Primary side circulation circuit 4 Compressor 5 Condenser 6 Cooling expansion valve 7 Heat exchanger (evaporator)
8 Hot gas bypass circuit 9 Hot gas expansion valve 10 Accumulator 11 Cooling water circulation circuit 12 Secondary side circulation circuit 1201 Cold water supply path 1202 Cold water circulation path 13 Temperature sensor 14 Control means 15 Pump

Claims (1)

A temperature control method for controlling the temperature of a control medium supplied to a temperature control target in various processes in semiconductor manufacturing to a predetermined temperature,
A primary side circulation circuit (3) for circulating the refrigerant;
A compressor (4) arranged in the middle of the primary side circulation circuit (3) for compressing the vaporized refrigerant to a high pressure, and for condensing the refrigerant made high pressure by the compressor (4) by heat exchange The condenser (5), a cooling expansion valve (6) for reducing the pressure of the refrigerant liquefied by the condenser (5), and the refrigerant reduced to a low pressure by the cooling expansion valve (6) A heat exchanger (7) for controlling the temperature of the control medium to a set temperature,
In the primary side circulation circuit (3), a bypass circuit for hot gas (between the compressor (4) and the condenser (5) and between the cooling expansion valve (6) and the heat exchanger (7)). 8) and
A hot gas for mixing a high-temperature refrigerant that has been increased in pressure by the compressor (4) with a refrigerant that has been reduced in pressure by the cooling expansion valve (6), disposed in the middle of the bypass circuit for hot gas (8). Expansion valve (9),
A refrigerator (2) comprising:
A secondary circulation circuit (12) that circulates the control medium between the temperature control target and the heat exchanger (7), and supplies the control medium controlled to a predetermined temperature in the heat exchanger (7) to the temperature control target; ,
Using a temperature control device equipped with
A temperature sensor (13) is disposed in the path of the secondary circuit (12),
According to the detection result by the temperature sensor (13), the opening degree of the cooling expansion valve (6) and the hot gas expansion valve (9) is adjusted, so that the control medium supplied to the temperature control target The heat exchanger (7) is controlled by controlling the temperature to a set temperature and controlling the opening of the cooling expansion valve (6) and the opening of the hot gas expansion valve (9) in inverse proportion to each other. The temperature control method characterized by adjusting the quantity of the refrigerant | coolant supplied to 1 to constant, and thereby making the circulation quantity of the refrigerant | coolant in a primary side circulation circuit (3) constant .

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